Simplish v2.1.10 makes one change to the styling for pre elements, removing the outline border box.
This release simply serves to get the very-slightly-different code we’ve run since the 2.1.9 release out into daylight.
It has had the benefit of production use and testing up to the latest WordPress svn tip (inclusive of the current release, 2.8.4, of course).
Download Simplish version 2.1.10 here, or see it soon in the WordPress themes directory.